The U.S. imprisons a higher proportion of its population than any country in the world—a trend driven by an increasingly punitive public.

New Measure of Punitiveness: A novel index tracks growing public support for tough-on-crime policies since 1953.

Key Findings: Regression analysis shows this public opinion is a fundamental driver of incarceration rate increases, controlling for crime rates, drug use trends, inequality levels, and party dominance. If punitiveness hadn't risen mid-century, U.S. imprisonment could have been 20% lower.

Policy Lag: Congressional attention data confirms that the public's punitive attitudes precede policy changes.